The people of Springfield are getting ready for Whacking Day, an annual event where people chase down and beat snakes to death with sticks. Homer is very excited, so much so that he's actual quite nimble and in shape as he trains for the upcoming festivities.
Meanwhile, Bart has been expelled from school for a prank that injures Superintendant Chalmers. Bart is home-schooled by Marge and it is during his schooling he and Lisa learn Whacking Day is a sham and was originally organized to beat up on the Irish.
The day comes and the snake hunt is on. Bart and Lisa learn snakes are attracted by sounds and use their stereo and Barry White's vocals to bring all the snakes into the house for safety. The kids convince the townspeople Whacking Day is bad and the snakes are set free.